There are a number of document copiers that are operable to produce collated sets of copies by making multiple passes of a single set of originals. During each pass the originals forming the set are fed in sequence, either fully automatically or semiautomatically, from a stack to an exposure station at which they are copied. By making only a single exposure of each original during each pass, it is possible to produce multiple sets of copies that are already collated without using sorting bins or the like. Suitable apparatus for feeding the originals semiautomatically or with each original being initially advanced manually is shown in U.S. Pat. No. 4,023,791, issued to Hori, et al., and in Hori, et al. application Ser. No. 755,181, filed Dec. 29, 1976.
It is desirable that the set of copies be not only collated, but also readily distinguishable or separable from one another. While it has been suggested that blank copy sheets be inserted after each pass to separate adjacent sets of copies, this expedient is wasteful, requires an extra control for the machine and after the copying operation is complete still requires the operator to examine the stack of copy sheets simply to find the separation points.
It is also desirable to provide a means for reminding the operator of how many copies have already been made. While there exist fully automatic feeders that advance each original to the exposure station a preselected number of times, thereby obviating the need to remind the operator, such feeders are generally more complicated and more expensive than the semiautomatic feeders referred to above.